Reproduction of the American Dog Tick, Dermacentor variabilis1 , under Laboratory and Field Conditions

Publisher Website
Google Scholar
Abstract
Female American dog ticks, Dermacentor variabilis (Say), engorged on an albino rat, wild-caught porcupines and a raccoon, were held at 6 constant temperatures in the laboratory and at fluctuating temperatures at ground level in grassland and woodland of a study area in southwestern Nova Scotia. Mean weights of engorged females ranged from 309.4 to 665.9 mg following detachment from porcupines and the raccoon, respectively. The highest mean total number of eggs deposited per female engorged on porcupines and the albino rat and held at 25°C was 4877 (range 597–7187). The number of eggs laid and weight of engorged preoviposition ticks were positively correlated for most temperatures except that at the suboptimal constant temperatures of 15° and 35.6°C the correlations were still positive but not statistically significant. The pattern of daily oviposition rates varied in shape and magnitude of peaks depending on the temperature at which the ticks were held. The avg peak daily oviposition was as high as 528 eggs/female on the 3rd day of oviposition and as low as 79 eggs/female on the 32nd day of oviposition for the ticks held at 29.7° and 15°C, respectively. Fluctuating temperatures in grassland and woodland and the porcupines and raccoon as hosts during May and June, 1976, were suboptimal for female ticks which produced less than half the mean total number of eggs that were produced by females engorged on the albino rat and held at a constant 25°C during the same period. Ticks feeding on the 3 host species produced viable eggs which had similar weights during the peak oviposition period. The viability of eggs was reduced towards the end of the oviposition period. Under field conditions, less optimal temperature ranges may reduce the maximum reproductive potential of D. variabilis .

This publication has 1 reference indexed in Scilit: